Sprockets for driving flat belts are usually made from stainless steel or plastic that is machined or molded. In food processing applications, sprocket drives are a particularly critical area for cleaning. It is important to be able to periodically remove the residual matters from the sprockets and on the rear side of the belt, in order to avoid bacteria growth and spoilage of the food processed on the belt. For this purpose sprockets have been designed with large openings to allow cleaning medium to pass from the side and reach the critical areas to be cleaned. Such sprockets are disclosed for use with modular belts in U.S. patent application Ser. No. 12/288,602. However, such sprockets are not ideally suited for use with flat (non-modular) belts. For example, as depicted in FIGS. 7A-7B, the shape of the teeth, and lack of support between adjacent pairs of teeth, allow a flexible belt to buckle as it is forced around the periphery of the sprocket while the belt is under tension. Over time, this buckling causes damage to the belt including cracks on the surface of the belt.
Accordingly, there is a need for an improved cleaning system that incorporates a sprocket for use with flexible belts and that avoids the above-described shortcomings.